Linear array of dual‐polarised slot‐coupled dielectric‐rod elements for wireless applications

Abstract

The design of a dual-polarised series-fed microstrip array antenna for wireless applications, especially in the 5150–5750 MHz band, is delineated in this study, which consists of 12 dielectric rods, fed by circular slots. The rod height can be exploited to improve antenna gain and control its azimuth beamwidth. Using circular slot elements with a central crossing point improves port isolation and cross polarisation. The array elements are fed via two series-fed six-element arms having 25 dB Taylor distribution in each polarisation. The given arms are fed from the centre. Regarding H-polarisation, the arms are fed with a 180° phase shift to improve isolation between the ports as well as the cross polarisation. Additionally, a reflector plane is placed behind the array to suppress back-lobe radiation. A prototype of the array antenna is fabricated and measured. The return loss of the antenna is over 10 dB, varying from 5.1 to 5.8 GHz, and the isolation exceeds 30 dB over the bandwidth. The measured and simulated patterns are presented for both polarisations.